In outline, such a battery comprises:
an electrochemical block constituted by a large number of electrochemical couples;
a network for irrigating said electrochemical couples with electrolyte;
a heat exchanger for externally dumping the heat generated during discharge;
a pump for ensuring that the electrolyte flows round the irrigation network and said heat exchanger; and
a device for storing electrolyte and transferring it to said electrochemical block when the battery is activated, said device including an electrolyte tank which is connected both to a gas generator and to an inlet to said pump.
A problem encountered when such a battery operates is the feed to the pump when the battery propelled vehicle is subjected to a steep inclination of the order of 45.degree. in order to change the depth at which the vehicle is immersed. Pump feed must also be ensured regardless of variations in the volume of the electrolyte in the electrochemical block during discharge, which variations may be due, for example, to variations in temperature and to variations in molar volumes.
The object of the present invention is to provide an activatable battery using Li/SOCl.sub.2 or Li/SO.sub.2 Cl.sub.2 couples and whose structure enables the above problem to be solved.